Sterile Filtration and Bioburden Control for the Processing of Biologics

APIs, Cell Culture Media, Buffers, Raw Ingredients, Water

Sterilizing & Bioburden | Prefilters | Services | Water | Resources

Protecting the Bioreactor From Unwanted Organisms and Contaminants

Sterile filtration ensures that everything entering the bioreactor meets requirements to optimize cell culture or fermentation growth. Incorporating prefiltration into this process will protect the life of the sterilizing filters and lower your overall filtration costs. Product solutions are discussed below.

Sterilizing and Bioburden Reduction Filtration in Biopharmaceutical Processes (1)


Downstream Sterilizing and Bioburden Reduction Filtration



Remove Impurities Before Chromatography and Assure Sterility During Final Fill

Filtration is a vital component in assuring efficient operation and maximum output of chromatography systems in purification processes. Contaminants to be removed can include endotoxins - charged particles that can prematurely consume resin capacity - and organic or inorganic particles in base solutions, buffer solutions and cleaning solutions used to regenerate the columns between batches. Removing these contaminants optimizes column performance and keeps them operating at the highest level.

Sterile filtration of biologics is a preferred method due to the product's heat sensitivity. To avoid degradation and loss of product during final fill CPF's application engineers work with you to:

  • Ensure proper testing 
  • Choose the best performing filter
  • Configure the filter based on filtration goals



Sterilizing insurance. Our PPS Filters are recommended for the most stringent and critical applications to insure 100% bacteria retention. This filter’s media consists of two identical, hydrophilic membranes. Pore sizes range from 0.03 to 1.2 µm.

PPS side by side layers (350 x 117 px)

Targeted bacteria retention.  DPPS filters deliver custom bacteria retention based on your fluids load. You choose the pore sizes of both the prefilter and final layer to achieve targeted results. The prefilter acts as both a bioburden reduction and particle removing filter.

DPPS side by side layers (350 x 117 px)

Sterilizing fluids with high particle loads. CPF’s HPPS Filters handle increased capacity and high particle loads with an integrated prefilter for particle removal and a sterilizing final filter. This dual layer model reduces multiple filtrations into a single step.

HPPS side by side layers (350 x 117 px)

Sterilizing & endotoxin removal. The PPC Filter consists of a double layer sterilizing membrane for stringent bacteria retention and it has been positively charged to remove any gram-negative bacteria debris. 

PPC side by side layers (350 x 117 px)


Bioburden Reduction

Bioburden reduction, non-sterilizing. BPS Filters reduce microbials in aqueous liquids when sterilizing is not required. These hydrophilic filters are available in single and dual layer configurations with a choice of pore sizes for each layer to provide the right level of retention.

BPS side by side layers (350 x 117 px)


Mycoplasma control.  When your goal is mycoplasma reduction, all CPF sterilizing filters rated at 0.10 micron will reliably reduce mycoplasma in your fluids. When a validation of  >log 7  removal is required, choose any CPF sterilizing filter rated at 0.03 micron.


Tank Vent & Process Gas Filtration

Tank Vent 500Protecting tank contents and the environment. CPF's PTR Filters are hydrophobic sterilizing filters made with  Polytetrafluoroethylene (PTFE) membrane to capture microbials as air/gas enters a tank. Likewise, as air/gas is released from the tank, the PTR filter protects operators and the environment in the surrounding work space.

Clarification & Prefiltration

Clarifying and prefiltering microbials and particulates found in APIs, raw ingredients, cell culture media, buffers and excipients will reduce the contamination load on the final filter. In processing applications where sterile product is critical and final filters carry the greatest cost, CPF prefilters do the bulk of filtration, resulting in:

  • fewer changeouts
  • extending the life of your sterilizing filters
  • lower overall filtration costs

High particle loads. BCWPS Filters, made from CPF's proprietary high capacity PES membrane, excel in protecting downstream filters. With its low binding characteristics, BCWPS filters are used for the clarification and prefiltration of products with high proteins and preservatives. Membrane prefilters, such as the BCWPS offer greater retention than a depth filter.

BCWPS side by side layers (350 x 117 px)

PGD side by side layers (2)High flow and particle removal. Our PGD Prefilters are made with pleated fiberglass depth media and have a high contaminant holding capacity while still delivering high flow rates. 

Fine particles in water, solvents PPD side by side layers (1)and chemicals. PPD Prefilters, constructed with pleated polypropylene depth media, are versatile filters offering broad chemical compatibility and high retention of fine particles in a variety of fluids used in pharmaceutical applications.

HLP side by side layers (1)Heavy solids content and contamination. CPF's HLP Prefilters, constructed with high-loft pleated polypropylene depth media, combine superior filtration capacity with exacting retention of fine particles.

GPC side by side layersEndotoxin removal. CPF's GPC Filter is a standalone endotoxin removal filter used for the filtration of aqueous fluids that contain negatively charged biological contaminants, such as endotoxin, virus and other cell fragments.

Filtration Solutions for Producing Point-of-Use, WFI, and Bulk Water


Bio/pharmaceutical Water Filtration


Critical Process Filtration will test your process stream on our product to ensure filter performance.

  • Verifying that our filters will meet your performance goals
  • Validating performance set forth by regulatory bodies
  • Assisting with protocol development and execution
Connect with an Applications Engineer about verifying/validating your filters.


Quality Assurance and Standards

Critical Process Filtration filters are designed for use in cGMP compliant processes. Our state-of-the-art manufacturing facility and quality-management system both meet ISO 9001:2015 standards. Each operation from assembly and test to cleaning, drying, and packaging is done in appropriately rated clean rooms, and each filter is assigned a lot code to ensure the traceability of manufacturing data and materials. A sophisticated MRP system collects and processes real-time data from manufacturing centers and inspection points. 

USP Biosafety and FDA Compliance

The materials used to construct pharmaceutical-grade filters are non-toxic and meet the requirements for the MEM Elution Cytotoxicity Test and the requirements for Biological Reactivity Tests in the current version of the United States Pharmacopeia (USP) for Class VI - 121 °C Plastics. Critical Process Filtration filters comply with Title 21 CFR sections 210.3 (b)(6) and 211.72, for non-fiber-releasing filters. The levels of bacterial endotoxins in aqueous extracts from pharmaceutical-grade filters are below current USP limits as specified for water for injection.